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    <script>
        // 参数的作用就是让函数更加灵活
        // 形参 函数声明时，写在函数名后面括号里面的，其本质是变量

        function getSum(n) {
            let sum = 0
            for (let i = 0; i <= n; i++) {
                sum += i
            }
            console.log(sum);
        }
        // 实参
        getSum(5)
    </script>
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